For patients in the investigational group, no additional surgical procedure at the involved level classified as a failure. For patients in the control group, no "treatment surgery" at the involved level that was the result of a poor response to conservative care treatment.

Neurological status is based on four types of measurements: motor, sensory, reflexes, and straight leg raising. Each of the sections is comprised of a number of elements. Overall neurological success will be defined as maintenance or improvement in all sections ( motor, sensory, reflex, and straightleg raising ) for the time period evaluated.

Numerical rating scales will be used to evaluate pain intensity and duration. The pain score (0 min, 20 Max) is derived by adding the numerical rating scores from the pain intensity (0-10, with a score of 0 representing "no pain" and a score of 10 representing "pain as bad as it could be.") and duration scales (0-10, with a score of 0 being "pain none of the time" and a score of 10 being "pain all of the time"). Success for back pain and leg pain is described as follows: Pre-treatment Score - Post-treatment Score >0

The Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) will be used to assess general health status. The SF-36 physical component summary (PCS) measures a patient's physical wellbeing and will be calculated according to algorithms formulated by the Medical Outcomes Trust. To be classified as a success, the following criterion must be met for SF-36 PCS:

This pivotal clinical trial is being conducted to evaluate the DIAM™ Spinal Stabilization System for the treatment of single-level moderate lumbar degenerative disc disease. The implant under investigation in this clinical trial is the DIAM Spinal Stabilization System, and the device will be implanted using a posterior surgical approach. Patients in the control group will receive nonoperative treatment.

Eligibility

Ages Eligible for Study:

18 Years to 70 Years

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Each patient participating in this clinical trial must meet all of the following inclusion criteria:

Has moderate low back pain secondary to lumbar degenerative disc disease at a single level from L2 - L5. Low back pain is defined as persistent back pain, with or without radicular pain, with current episode of less than one year duration. Degenerative disc disease is confirmed by patient history, physical examination, and radiographic studies with one or more of the following factors (as measured radiographically by MRI scans or x-rays):

Decreased disc height >2mm, compared to the disc space at the next adjacent (superior or inferior, whichever has greater disc height) spinal level;

Has pre-treatment back pain score of ≥ 8 based on the Pre-Treatment Back and Leg Pain Questionnaire (Back Pain Intensity + Back Pain Frequency).

Has been treated nonoperatively (e.g. bed rest, physical therapy, medications, TENS, manipulation, and/or spinal injections) for a period of at least 6 weeks and not more than 6 months prior to enrollment in the clinical study.

If of child-bearing potential, patient is not pregnant or nursing and agrees not to become pregnant during the study period.

Is willing and able to participate in either of the randomized treatments for the duration of the study follow-up period. If the patient is randomized to the investigational group, he/she is willing to undergo surgery and receive the DIAM device. If the patient is randomized to the control group, he/she is willing to undergo all four nonoperative treatments.

Is willing and able to comply with the study plan and able to understand and sign the Patient Informed Consent Form.

Exclusion Criteria:

A patient meeting any of the following criteria is to be excluded from this clinical trial:

Has disc height loss > 67% at the involved level, compared to the next adjacent (superior or inferior, whichever has greater disc height) spinal level

Has Arachnoiditis.

Has a primary diagnosis of a spinal disorder other than degenerative disc disease at the involved level.

Requires treatment of degenerative disc disease at more than one lumbar level.

Has had all of the following nonoperative treatments (prescribed medications, active physical therapy, spinal injections, and patient education) within the past 6 weeks.

Has a sequestered herniated nucleus pulposus.

Has had any previous surgery at the involved or adjacent spinal levels (including procedures such as rhizotomy).

Has any disease (e.g., neuromuscular disease) that would preclude accurate clinical evaluation of the safety and effectiveness of the treatment regimens in this study.

Has received treatment with an investigational therapy (device and/or pharmaceutical) within 30 days prior to entering the study or such treatment is planned during the 24 months following enrollment in the study.

Has an implantable metal device (e.g., stimulator, pacemaker) and is unable to have an MRI.

Is an alcohol and/or drug abuser, as defined by currently undergoing treatment for alcohol and/or drug abuse.

Is mentally incompetent. If questionable, obtain psychiatric consult.

Has a Waddell Signs of Inorganic Behavior score of 3 or greater.

Is a prisoner.

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00456378